Contract no.: 30N/12.01.2023
The project: „Dezvoltarea de soluții inovatoare și tehnologii de fabricație avansată cu laseri, plasmă și radiații pentru rezolvarea problemelor societale„
Faza 18/2025: „Realizarea instalației de procesare laser aditivă și substractivă în configurație 3D (PL1.9) – final etapa II„
Responsible for this: Dr Marian ZAMFIRESCU
The term of the conclusion of the phase: 09.12.2025
Abstract:
Any laser workstation has as essential components the optoelectronic and mechanical modules for monitoring and controlling the sample position and the focusing of the laser beam on the sample. At this project phase, the sample visualization system was configured, consisting a modular optical microscope, integrated into the laser workstation. The optical system is designed in a confocal configuration with variable focus element distance. The device includes an electronic command and control system for synchronizing the laser pulses with other equipment, such as motorized translations, beam attenuators and shutters. The control units of the subassemblies provide electronic input and output ports, digital inputs/outputs and analog interfaces. Several devices can be synchronized via their external synchronization ports (Trigger). The operators interact directly with a graphical software interface (GUI) that provides common controls such as buttons, radio buttons, text inputs and text areas. Behind any intuitive interface are lines of code for decision blocks and algorithms. Any complex programming script for laser processing includes, as a basic library, at least a few essential commands for elementary movements: home(), move_abs(), move_rel(), laser_on(), laser_off(), get(), stop(). For maximum performance, specific conditions for the working environment in which the processing station operates are also ensured. The main environmental factors that influence the quality of processing are temperature, vibration, dust and humidity. Operator training is equally important. Rules and procedures for laser safety are another factor that is taken into account for an apropiate work of operators with this laser micro-processing device.
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Contract no.: 30N/12.01.2023
The project: „Dezvoltarea de soluții inovatoare si tehnologii de fabricație avansată cu laseri, plasmă și radiații pentru rezolvarea problemelor societale„
Faza 19/2025: „Caracterizarea surselor de plasmă obținute din punct de vedere funcțional (operațional). Stabilirea parametrilor optimi de funcționare (PL1.8)„
Responsible for this: Dr Corneliu POROȘNICU
The term of the conclusion of the phase: 09.12.2025
Abstract:
During this phase, a functional, improved and optimized experimental device of the thermal plasma spray source at atmospheric pressure for the deposition of thin and thick layers of calcium phosphates was developed. The functionality of the system was tested for different working gases (Ar, N2, N2 – O2 mixture in proportions of 80-20%), under various gas flow conditions and plasma source supply current intensities. The experimental device as well as the testing of its components were entirely realized in INFLPR. The thermal plasma jet was characterized optically and spectrally by OES, and the layers were characterized by Fourier Transform Infrared spectroscopy and scanning electron microscopy.
The results obtained allowed the identification of the optimal operating conditions of the device with a thermal plasma spray for calcium phosphate layers production with properties identical to those of the precursor powder.
The objective of the phase was also to develop a fast camera imaging method for analyzing the dynamics of a plasma jet with Al₂O₃ microparticles. The methods from the previous stage of analyzing plasma flow in RF discharge were used. For the deposition process, optical flow-based imaging was applied, which determines the local velocity field from the intensity variations between successive frames captured with an ultrafast camera. Optical flow measures the displacement of pixels, being ideal for fast movements and fine spatial variations. The plasma jet directs the powder towards the substrate; images were acquired with the Photron camera at 60 fps. Preprocessing included CLAHE for local contrast and Gaussian filtering for noise reduction, highlighting edges and details. The proprietary method uses the Farnebäck algorithm, which estimates dense two-dimensional displacements per pixel, robust to illumination variations – superior to Lucas-Kanade (limited to points of interest). It uses a multiresolution pyramid, starting from the bottom, with iterative refinement.
The study presents also the synthesis of tungsten nitride nanoparticles using an MSGA source, achieved by employing an N₂–H₂ mixture in the discharge. H₂ introduction into the discharge increased the deposition rate, compared to the very low (almost negligible) rates obtained with only N₂. The morphological analysis of the deposited material reveals the formation of nanostructured films consisting of aggregates of nanoparticles with diameters of 6–17 nm. Chemical analysis indicates the presence of W₂N and WO₃, suggesting that further studies are needed to improve the nanoparticles' purity. TRL4-level technical documentation has been developed for the production of metallic W nanoparticles using the MSGA source.
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